RETA
Spain's special Social Security regime for the self-employed ("autónomos").
RETA (Régimen Especial de Trabajadores Autónomos) is the branch of the Spanish Social Security system that self-employed workers ("autónomos") must register with and pay monthly contributions to, separate from the general regime that covers salaried employees.
It matters for fast-loan applicants because Spanish lenders assessing a self-employed applicant's income typically look at RETA contribution history and tax filings (rather than a standard nómina/payslip) as proof of stable, recurring income when a payslip isn't available.